1. Field of the Invention
The invention relates to a device for detecting and displaying the position of components of vehicle couplings according to the preamble of claim 1.
2. Description of Related Art
A device is known from DE 102 41 904 A1 for displaying the locked status of a fifth-wheel coupling wherein a first sensor is located in the area of the insertion opening of the fifth-wheel coupling to detect the kingpin, and a second sensor comprises a magnetically-sensitive sensor that interacts with a magnet affixed to the control handle, and both sensors contact different actuating mechanisms. The sensors are connected to a display unit in the cab of the semi-trailer truck.
Generally, the signals of the sensors are transmitted and the energy of the sensors is supplied through cable harnesses, and the signals are evaluated by corresponding control electronics. The installation expense for such systems is large, and often stands in poor relationship to the achieved effect, which hinders widespread use of such desirable safety-enhancing features. In U.S. Pat. No. 6,736,420 B2, a displacement device for fifth-wheel couplings is known that has two guide rails with toothed bars on which a carriage is moveably mounted that bears the fifth-wheel coupling. Located on the carriage is a locking device having blocking parts that engage in the toothed bars. One of the blocking parts is connected to an opening lever that in turn can be connected to an actuating device, for example, a pull lever for manual actuation. With this known displacement device, it is also necessary for the driver to visually check that the carriage is properly locked before he starts driving.
Independent of the presence of display mechanisms in the cab, the driver must visually check the vehicle, fifth-wheel coupling, locking device, etc. before driving.
Usually, mechanical locking displays are used that, depending on the design and lighting, are easier or more difficult to read. This can make it much more difficult to check the vehicle before driving and, in an extreme case, can lead to incorrect coupling.